A rectangular worked stone of limestone with rounded corners measuring 0.35m 0.30m, which sits 1.20m east of Locus 4 and is abutted by Locus 14. Locus 4 is a worked stone feature that lies on the same line as worked stone feature Locus 4. Loci 4 and 15 are different in shape but similar in size. They bear marks that indicate tool use. Locus 15 lies in a line of similar worked stones, including Locus 4. There are three lines of such stones. They are in most cases surrounded and lipped by very compact plaster surfaces. Locus 15 is a column pad in the workshop structure. It likely supported a wooden column which supported the roof of the workshop. It is surrounded by plaster floor which functioned as the working surface of the workshop. The plaster floor was constructed around the column pads after they were deposited.